fix(rbo,rules,QA): ExistsFilter::transform merges statistics to enable QA for EXISTS expressions.

dbcon/execplan/calpontselectexecutionplan.cpp

@@ -1182,12 +1182,17 @@ execplan::SCSEP CalpontSelectExecutionPlan::cloneForTableWORecursiveSelectsGbObH
   // Deep copy of column map
   for (const auto& entry : fColumnMap)
   {
-    // WIP only relevant RCs must be copied
-    if (entry.second)
+    auto tableAlias = entry.second->singleTable();
+    // TODO We insert multiple times if there are multiple SCs for the same RC.
+    if (tableAlias && targetTableAlias.weakerEq(*tableAlias))
+    {
+      auto it = fColumnMap.find(entry.first);
+      if (it == fColumnMap.end())
       {
         newColumnMap.insert({entry.first, SRCP(entry.second->clone())});
       }
     }
+  }
 
   newPlan->columnMap(newColumnMap);
 

dbcon/mysql/ha_exists_sub.cpp

@@ -127,6 +127,9 @@ execplan::ParseTree* ExistsSub::transform()
     return NULL;
   }
 
+  // Insert column statistics
+  fGwip.mergeTableStatistics(gwi.tableStatisticsMap);
+
   // remove outer query tables
   CalpontSelectExecutionPlan::TableList tblist;
 

dbcon/rbo/rbo_apply_parallel_ces.cpp

@@ -441,6 +441,8 @@ execplan::SCSEP createDerivedTableFromTable(execplan::CalpontSelectExecutionPlan
   }
 
   {
+    derivedCSEP->tableAlias(tableAlias, true);
+
     auto additionalUnionVec = makeUnionFromTable(
         *derivedCSEP, const_cast<execplan::CalpontSystemCatalog::TableAliasName&>(table), ctx);